1. Field of the Invention
The present invention relates to suspension systems for gyrocompasses and similar devices which require isolation from their mounting surfaces, and more specifically to a suspension system for isolating such devices from vibrations having low resonant frequencies on the order of 5 Hz or less.
2. Description of the Prior Art
Suspension systems used heretofore to isolate gyrocompasses and similar devices typically can not provide isolation from vibrations having low natural frequencies in all directions along a set of principal orthogonal axes. Consequently, existing suspension systems do not have correlation between the vertical (z axis) and the horizontal (x and Y) axes. Typically, coil springs have been used without success to isolate gyrocompasses and similar devices from vibrations having a natural frequency of less than 5 Hz along all axes. In such suspension systems coil springs are mounted vertically to provide isolation from vibrations having low natural frequencies in the vertical direction, but spring stiffness rates and damping coefficients of the coil springs do not provide sufficient isolation from vibrations having low natural frequencies along the horizontal x and y axes. Those skilled in the art, therefore, have attempted to solve this problem of horizontal isolation with various methods, but they have met with little or no success. Typically, the methods used have included leaf springs disposed against the sides of the device to be isolated; rubber "wobble" plates having a post embedded therein or vulcanized thereto; compression or extension springs either horizontally or diagonally mounted to the device; or using the vertically mounted coil spring to provide horizontal spring stiffness. Accordingly, there is a need for a suspension system which correlates springs, dampers, and shock snubbers into a suspension system which provides isolation from vibrations having low frequencies in all directions.